Bulb only has one variable tariff for households paying by direct debit, and one tariff for those on prepayment meters. The price of both will rise on 19 April, meaning all Bulb’s customers will pay more. Both unit prices and the daily standing charge is increasing.

Bulb’s Vari-Fair tariff currently costs £966 a year on typical use. It will increase by £91 to £1,057 a year. Its Vari-Fair prepay tariff is currently £1,010 a year on typical use. It will increase by £137 to £1,147 a year.

Bulb said the price rises were due to an increase in the cost of supplying energy. However, it pointed out that even after the prices rises, its tariffs would still be below the energy price cap, and that it had delayed putting up prices for as long as it could.

Bulb will be in contact with all its customers between Wednesday 17 March and Friday 19 March to explain what the changes mean for them.

For current Bulb customers, all rates will change on Monday 19 April. Bulb doesn’t charge exit fees, so customers are free to switch suppliers at any time without penalty.

People who switch to Bulb from now onwards will be on the new rates once their switch completes, apart from those who top up at a shop for their energy. Customers with top up meters will be on the new rates from 19 April. Rates vary by area and these are shown on the tariff page on the Bulb website.

From 1 April, the energy price cap set by Ofgem will rise by £96 from £1,042 to £1,138, primarily driven by a global recovery in wholesale energy prices in recent months. For customers paying by prepayment meter, the level will rise by £87 from £1,070 to £1,156.

Bulb says its typical energy bills will be £81 below the new post-pay energy price cap, while its prepay rates will be £9 below the prepayment price cap.

Bulb says wholesale energy costs are now 31% higher than they were in September when it last changed prices.

EDF, E.ON, Npower , Scottish Power and British Gas are all raising prices by the maximum allowed under the April energy price cap.